Abstract: An energy storage system is provided, including: a plurality of energy storage devices, wherein each energy storage device includes an energy source; a junction unit for connecting the plurality of the energy storage devices in parallel to a common power bus, the junction unit including a control circuit; a power conversion unit coupled to the common power bus; and protection circuitry coupled to the control circuit for preventing current from one of the energy storage devices from flowing to another of the energy storage devices.

Abstract: An energy efficient data center incorporating superconducting power transmission cables coupled with cryogenically cooled semiconductor inverters and converters, used to supply power to cryogenically operated or room-temperature computers and servers. Other options and features include a lighting system whose performance is enhanced by the cold temperatures, fiber optic connections operated at cryogenic temperatures, integrated renewable energy power sources, advanced energy storage technologies, cryogenically operated computers, and a number of other cryogenic hardware. The operating temperature of the cryogenic components can be anywhere in the range between 0 K and 200 K, with other components operating above 200 K.

Abstract: An energy efficient data center incorporating superconducting power transmission cables coupled with cryogenically cooled semiconductor inverters and converters, used to supply power to cryogenically operated or room-temperature computers and servers. Other options and features include a lighting system whose performance is enhanced by the cold temperatures, fiber optic connections operated at cryogenic temperatures, integrated renewable energy power sources, advanced energy storage technologies, cryogenically operated computers, and a number of other cryogenic hardware. The operating temperature of the cryogenic components can be anywhere in the range between 0 K and 200 K, with other components operating above 200 K.

Abstract: Described is a novel aircraft lighting system with the potential for achieving increased efficiency, improved thermal management, higher reliability, and longer lifetimes. The proposed approach involves combining solar cells and light-emitting diodes (LEDs), and utilizing the cold temperatures of about ?50 degrees centigrade encountered in high-altitude (12,000 m) flight to improve thermal management and efficiency in both components.

Abstract: A bi-directional power converter for cryogenic operation based on a bi-directional cryo-MOSFET switch. Cryogenic power electronics lends itself easily to bi-directional topologies, and brings higher efficiencies, further reductions in switching speed, higher-frequency operation, reduction in size and weight of associated transformers and inductors, and reductions in overall size and weight. In addition, cryogenic power electronics operating around liquid nitrogen temperatures is easily integrated with superconducting motors, motor drives, and transformers, all of which can reduce size and weight of shipboard power systems, allowing for greater payload.

Abstract: An ultra compact ring topology puts the output terminals of solid state switches physically at the center of a circuit with the switches surrounded by voltage busses. The switches are symmetrically arranged around the output bus, the voltage busses are filtered (decoupled) to ground using symmetrically positioned filter components, and lead lengths to and from the switches are minimized. Switch driver circuits are closely integrated with each switch and positioned as close as possible, each to its associated switch, and arranged symmetrically. Switches may be at cryogenic temperatures and busses and lead connectors may be superconductive.

Abstract: This invention describes a means by which performance characteristics of capacitors can be improved. This is achieved by reducing the temperature, preferably but not exclusively to cryogenic temperatures below 100 K. The dielectric strength, dielectric losses, equivalent series resistance, and plate losses in many capacitors, such as film capacitors, improve as the temperature is decreased. Current carrying capacity is improved. A capacitor bank exhibits energy densities up to four times those of conventional, room-temperature capacitor banks. Cryogenic capacitors can be combined with cryogenically operated semiconductors or with superconductors to reduce the size, weight, and losses of a complete system.

Abstract: An electrical switching topology for a hybrid switch provides extremely low losses in both cryogenic and non-cryogenic electronic systems. In this switch having switch modules connected in parallel, switching losses in a first module are separated from conduction losses in the parallel-connected second module. The conduction losses are then further reduced by cryogenically cooling the second module. Since the switching losses of the first module can be absorbed outside a cryogenic container, the switching losses do not add to the cryogenic heat load. In other applications, the switching module operates at lower temperatures to provide higher switching speeds and reduces switching heat generation.

Abstract: Switching losses and conduction losses are isolated by networks which are partially cryogenic and partially at room temperature. Switching losses are independent of temperature. Advantageously the switching losses are taken in a snubber network at room temperature and conduction losses are incurred at cryogenic temperatures, where majority carrier devices like MOSFETs operate with ultra low on-state resistance and corresponding low conduction losses. Low loss leads carry current efficiently from the cryogenic environment to room temperature without adversely affecting refrigeration. Switch and snubber network may both operate cryogenically.

Abstract: The highest-power switches now available are based on thyristor-type devices: GTOs (Gate turn-off thyristors), MTOs (MOS controlled turn-off thyristors), IGCTs (Integrated gate commutated thyristors), and the new ETOs (Emitter turn-off thyristors). These devices handle kilovolts and kiloamperes for megawatt inverters/converters. Measurements by the inventors show that conduction losses of MOSFETs and switching losses of IGCTs are drastically decreased by cryo-cooling. IGCTs, ETOs, and MTOs, together with many small, low voltage MOSFETs for gate and emitter turn-off circuitry, are cryo-cooled to attain much higher switching speeds and a reduction in size, weight and cost of high-power (megawatt range) equipment.

Abstract: This invention describes a means by which performance characteristics of capacitors can be improved. This is achieved by reducing the temperature, preferably but not exclusively to cryogenic temperatures below 100 K. This is based on the observation that the dielectric strength, dielectric losses and plate losses in many capacitors, such as film capacitors, improve as the temperature is decreased. A cryogenic capacitor bank is also described, which exhibits energy densities up to four times those of conventional, room-temperature capacitor banks. Cryogenic capacitors can be combined with cryogenically operated semiconductors or with superconductors in such a way as to reduce the size, weight, and losses of a complete system.

Abstract: Losses are reduced in electrical conductors and filters, especially those made with superconducting cables or inductors, which carry currents having both direct current (DC) and alternating current (AC) portions as in rectifier busses and power distribution systems. Superconducting cables and chokes are capable of passing direct current with practically zero losses, but they exhibit considerable AC losses. A low impedance AC bypass of the superconducting cables and chokes minimizes these losses.